Super Confused About GetOwner()

[Lucid_Stew]

I didn’t understand why we were getting owner here and checking for it or why we’re using the AActor pointer rather than ‘this’ to pass the return of the GetInstigatorController() function into the ApplyDamage() function. I went on a journey of discovery in the docs and ended up even more confused than when I started. What does GetOwner() do exactly? The documentation is sparse and I feel like I’m going in circles.

[DanM]

@Lucid_Stew

I didn’t understand why we were getting owner here

To not self-inflict damage. The owner was set to be the tank or turret that shot the projectile.

@Lucid_Stew

or why we’re using the AActor pointer rather than ‘this’

Because that argument is what you want to apply damage to. Passing this would be the projectile that just hit something.

@Lucid_Stew

to pass the return of the GetInstigatorController()

That argument is for the controller responsible for the damage which would be the controller of the tank/turret.

@Lucid_Stew

What does GetOwner() do exactly?

Get’s the owning actor of the actor or component. For a component it’s whatever the component is attached to. For an actor it’s whatever you decide it to be. It is nothing if not set.

[Lucid_Stew]

Hi Dan, thanks for the reply. I wasn’t clear on one part, unfortunately, so let me rephrase from my point of view. Maybe I’m thinking about some things wrongly, don’t know.

‘this’ acts like a pointer to the instance.
if an object is not owned by something, GetOwner() returns a pointer to itself, correct?

In that case ‘this’ and pointer returned by GetOwner() would be equivalent?

So here we are checking GetOwner() just in case as a general rule?

And then along the same lines, we use MyActor->GetInstigatorController() rather than this->GetInstigatorController() for the same reasons?

[DanM]

@Lucid_Stew

‘this’ acts like a pointer to the instance.

It is a pointer to the instance executing that code.

@Lucid_Stew

if an object is not owned by something, GetOwner() returns a pointer to itself, correct?

Incorrect, it would return nullptr

@Lucid_Stew

And then along the same lines, we use MyActor->GetInstigatorController() rather than this->GetInstigatorController() for the same reasons?

They would do completely different things. this->GetInstigatorController() is exactly the same as GetInstigatorController()

[Lucid_Stew]

Unattached, by default an object owns itself though, right?

Maybe a better question at this point: in the above code snippet, what is the owner?

[DanM]

@Lucid_Stew

by default an object owns itself though, right?

Again, no.

@Lucid_Stew

Maybe a better question at this point: in the above code snippet, what is the owner?

Answered previously. The tank or turret that shot it. You yourself set this.

AProjectile* Projectile = GetWorld()->SpawnActor....;
Projectile-SetOwner(this);

[Lucid_Stew]

Hey Dan, thanks a ton for your patience. A lot of my misunderstanding there stemmed from forgetting that we set the owner.